90191000 has 32 divisors (see below), whose sum is σ = 211049280. Its totient is φ = 36076000.

The previous prime is 90190993. The next prime is 90191029. The reversal of 90191000 is 19109.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44096 + ... + 46095.

It is an arithmetic number, because the mean of its divisors is an integer number (6595290).

Almost surely, 2^90191000 is an apocalyptic number.

It is an amenable number.

90191000 is an abundant number, since it is smaller than the sum of its proper divisors (120858280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

90191000 is a wasteful number, since it uses less digits than its factorization.

90191000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90212 (or 90198 counting only the distinct ones).

The product of its (nonzero) digits is 81, while the sum is 20.

The square root of 90191000 is about 9496.8942291678. The cubic root of 90191000 is about 448.4572685503.

The spelling of 90191000 in words is "ninety million, one hundred ninety-one thousand".